EP4188819A1

EP4188819A1 - Reusable envelope with pre-cut closure flap, method and machine for manufacturing such an envelope

Info

Publication number: EP4188819A1
Application number: EP21742440.7A
Authority: EP
Inventors: Freddy OBERHAUSSER; Marc FRIEDERICH
Original assignee: Holweg Group SAS
Current assignee: Holweg Group SAS
Priority date: 2020-07-30
Filing date: 2021-07-16
Publication date: 2023-06-07
Anticipated expiration: 2041-07-16
Also published as: EP4188819B1; FR3113036B1; US20230312181A1; WO2022023093A1; FR3113036A1

Abstract

An envelope comprises a closure flap (14) for closing and opening (15) by folding over a first wall (11) of the envelope (1) and comprises, on an inner face (140), a first adhesive layer (141) protected by protection means (17) formed by a sheet, a second adhesive layer (142) protected by the protection means (17) and separated from the first adhesive layer (141) by a separation space (144), the flap (14) being pre-cut by a first and a second weakening line (181, 182) in the separation space (144), the sheet extending over the two adhesive layers (141, 142) and comprising a third weakening line (183) aligned with the first weakening line (181) and a fourth weakening line (184) aligned with the second weakening line (182). Method and machine for manufacturing such an envelope.

Description

Reusable envelope with pre-cut closure flap, method and machine for manufacturing such an envelope

Field of invention

The invention relates to a reusable envelope, in particular made of a flexible material such as paper. It also relates to the process for manufacturing the envelope as well as a machine for manufacturing said envelope.

Industrial processes for manufacturing bags made of flexible material such as paper or synthetic material have long been known. For example, document FR 1 270 400 describes a machine and a method in which a strip is unwound and then formed into a casing. The casing is flattened so that it comprises a first and a second wall, then the casing is cut into sections so that at each end of the section there remains a tab which extends the first or the second wall. In a folding step, the tab is folded and glued by being folded over the wall other than that from which the tab originates. It is thus possible to manufacture bags at a high rate with a wide variety of materials and formats. Document FR 786 579 shows several examples of this technique. It shows in particular in Figures 4 to 6 a manufacturing process in which the strip of paper is provided at regular intervals with lines of transverse perforations, with a line in the center and two lines, axially offset from the center line on each tape length.

The casing is formed by folding each edge over the central part and by gluing the two edges together along a central junction so that the perforations form two transverse lines offset respectively on one and the other of the faces of the casing. The casing thus formed passes between a pair of drive rollers which drive the casing at a constant speed. The front part of the casing is gripped by the folding device which comprises a drum and a counter-rotating folding roller. The drum and the folding roller rotate with a higher peripheral speed than the pair of drive rollers. The folding roller has a bar adapted to pinch the front of the casing against the drum, so that the front part of the casing is pulled and separated by tearing along the perforations to form a section. On separation, due to the offsets between the perforation lines, a rear leg is thus formed on the section, as well as a front leg at the end of the casing. This front leg will end up on the next stretch. The front tab is folded by the folding device over a glued area to close the front part of the section. For this, the roller further comprises a folding blade, placed just behind the bar, which pushes the casing into a gripper carried by the drum so as to bend the casing.

In a variant, the casing is formed with bellows which connect the first and the second wall. Document WO 2016 097310 A1 shows an example of such bags. This document also shows a machine making it possible to form an envelope from the casing by using two stations each comprising a pair of counter-rotating cylinders and whose work makes it possible to carry out the separation into sections and the tearing of a waste to reveal a leg at the front of the stretch on the same wall as the rear leg. Thus, after folding the tabs, they are applied to the same wall.

Such bags can be used as shipping envelopes. In this case, the rear tab is provided with an adhesive layer, for example protected by protective means such as a sheet of silicone paper. This sheet can be removed, revealing the adhesive layer. The back tab serves as a closing flap which can be folded back by bringing the adhesive layer against the wall opposite to that whose back tab is WO 2016 097310 A1 issue, so that the adhesive layer sticks to the wall and seals the envelope. Thus, the wall from which the tabs come has a smooth face when the tabs are glued to the opposite face to close the envelope. When the envelope is received by its recipient, the latter tears off the end of the envelope, for example at the level of the flap, to access its content.

To make such an envelope, the method as described above is modified to include the deposition of the adhesive layer and protective means on the adhesive layer before forming the casing. The location of the deposit is set in such a way that the means of protection are uncovered on the hind leg when separating the sections. GB 390,455 shows a method of applying a transparent window to a web of paper before forming an envelope. This same technique is used to deposit the means of protection on a previously deposited adhesive layer.

Such an envelope can only be used once. However, it is increasingly common, especially in mail order or internet commerce, for the original recipient to wish to return the item received. In this case, he must obtain another envelope.

It has been proposed in US 5,503,328 an envelope that can be used more than once. For this, the flap has two adhesive layers separated by a separation space. Each adhesive layer is protected by a protective sheet. The separation space receives a tear strip. During a first shipment, the protective sheet of the outermost adhesive layer is removed and the flap folded down so that the adhesive layer sticks to the envelope, so as to close it. To open it, the recipient pulls on the tear strip so that the flap tears at the separating space. The recipient can thus reuse the envelope by removing the second protective sheet and folding down the remaining part of the flap so that the second adhesive layer sticks to the envelope to close it.

Although satisfactory, this envelope is complicated to manufacture. In particular, the deposition of the tear strip which is made of a resistant material is done by unrolling the strip, which requires that the flap be parallel to the direction of movement during the production of the envelopes. The production rates of this type are lower than those of envelopes with the method of document WO 2016 097310 A1.

It is therefore an objective of the invention to propose an envelope which can be reused while being produced at high speed.

With these objectives in view, the subject of the invention is an envelope comprising an opening and a closing flap for closing the opening, the closing flap being hinged on a first wall of the envelope and comprising on an inner face a first adhesive layer protected by protective means, a second adhesive layer protected by the protective means and separated from the first adhesive layer by a separation space, the flap being pre-cut by a first and a second line of weakness in the space separation, characterized in that the protection means are formed by a sheet extending over the two adhesive layers, the sheet comprising a third line of weakness aligned with the first line of weakness and a fourth line of weakness aligned with the second line of weakening.

Such an envelope is reusable insofar as the shutter can be closed for the first time by detaching the protective sheet to release the first layer of glue and stick the first adhesive layer on the first wall, then the envelope can be opened by tearing the strip of material delimited between the first and the second line of weakness and the part of the sheet located between the third and the fourth line. Finally, the envelope can be closed a second time by releasing the second adhesive layer by removing the rest of the sheet to stick it on the first wall. Such an envelope can be productively produced by being produced entirely continuously and without rework. The protective sheet is wide enough to be able to be deposited in a movement along its transverse direction, as will be seen subsequently.

According to an improvement, the sheet and the shutter are glued between the lines of weakness. The detachment of the strip is then more surely achieved, due to the cohesion of the part coming from the flap and that coming from the sheet.

According to one embodiment, the lines of weakness are lines of perforations. The size and spacing between perforations can be adjusted to adjust the weakening of the web of material.

According to another embodiment, the lines of weakness are pre-cut lines in the thickness. Such lines are made by pressing the flap with a thin blade against a hard surface without crossing the entire thickness. A tear is then guided along this line of weakness when removing the strap.

According to one arrangement, the casing comprises a second wall, from which the flap comes, and connected to the first wall along the outer edges of the first wall. The connection between the first and the second wall occurs because the strip of material is folded between the two, which makes a strong connection.

In a particular way, the first and the second wall are connected by bellows extending along the outer edges. The bellows are also made from the same strip of material by making folds. The envelope can contain thick contents while being resistant.

According to an improvement, the shutter has a notch at at least one of the ends of at least one of the lines of weakness. Thus, the notch initiates the tearing of the strap.

The invention also relates to a method for manufacturing an envelope as described above, according to which a closing flap is formed in the extension of a second wall of the envelope, two parallel adhesive layers are deposited on the flap to each other and separated by a separation space, characterized in that a sheet forming protection means is deposited on the two adhesive layers, the sheet and the flap are weakened together to produce a first line of weakening in the flap separation space aligned with a third line of perforation in the sheet, and a second line of perforation in the flap separation space aligned with a fourth line of weakness in the sheet, the lines of weakness extending parallel in the separating space. Lines of weakness that are made together are therefore guaranteed to align.

According to one embodiment, the envelope is formed from a strip of flexible material on which the adhesive layers and the protective sheet are first deposited, then the strip is closed in a hose by joining the strips of the band, then the casing is separated into sections leaving the flap at a first end of the section, each section forming an envelope after the closure of a second end opposite the first end. This process is a modification of a traditional casing manufacturing process, in which the protective means and the adhesive layers are added before the casing is formed.

In particular, the lines of weakness are produced after the casing has been separated into sections.

According to another embodiment, the casing is formed from a strip of flexible material closed in a hose by joining the lengths of the strip, then the hose is separated into sections leaving the flap at a first end of the section. , each section forming an envelope after the closure of a second end opposite the first end, and component on which are made the removal of the adhesive layers, the protective sheet and the lines of weakening. This process is a modification of a conventional envelope manufacturing process, in which the protective means and the adhesive layers are added after the formation of the envelope or a blank of the envelope.

The invention also relates to a machine for manufacturing an envelope implementing a method as described above, the machine comprising a device for forming a casing for forming a casing from a strip of flexible material, a device for separating a section of the casing at the front of the casing by forming a closing flap at one of the ends of the section of casing, the flap extending the section beyond the end of a first wall, the machine being characterized in that it comprises first depositing means for depositing on the strip of material two adhesive layers parallel to each other and separated by a separation space at the level of the closing flap, the depositing means being provided for further depositing a sheet forming protection means on the two adhesive layers, the machine further comprising weakening means for producing together a first line of weakening and a third line e of attenuation on respectively the shutter and the sheet aligned and in the separation space of the shutter, and together a second line of weakness in the separation space of the shutter aligned with a fourth line of the sheet, the lines d attenuation extending parallel in the separation space.

According to one embodiment, the depositing means are located upstream of the casing-forming device. Thus, the depositing means can be inserted upstream of the casing-forming device, for example by a block having its own frame.

According to another embodiment, the depositing means are located downstream of the casing separation device. The depositing means can be inserted on the same frame as the separation device, which avoids providing a specific frame.

According to a constructive arrangement, the means of weakening are located downstream of the device for separating the casing and the depositing means.

According to a constructive arrangement, the machine comprises a bottom forming device to form the casing with each section of casing by closing the front of the section of casing.

The invention will be better understood and other particularities and advantages will appear on reading the description which follows, the description referring to the appended drawings among which:

Fig. 1: Fig. 1 is a perspective view of an enclosure according to one embodiment of the invention;

Fig. 2: Fig. 2 is a view similar to FIG. 1 of the envelope ready to be sealed for the first time;

Fig. 3: Fig. 3 is a view similar to FIG. 1 of the sealed envelope for the first time;

Fig. 4: Fig. 4 is a view similar to FIG. 1 of the envelope being opened;

Fig. 5: Fig. 5 is a view similar to FIG. 1 of the envelope ready to be sealed for a second time;

Fig. 6: Fig. 6 is a view similar to FIG. 1 of the sealed envelope for a second time;

Fig. 7: Fig. 7 is a schematic view of an envelope making machine of FIG. 1 according to a first embodiment;

Fig. 8: Fig. 8 is a schematic view of an envelope making machine of FIG. 1 according to a second embodiment.

An envelope 1 in accordance with one embodiment of the invention is shown in FIGS. 1 to 6. The envelope is made of a flexible material such as paper or a woven or non-woven synthetic material. The casing 1 comprises a first wall 11 and a second wall 12 superimposed and connected by gussets 13 extending along outer edges 110. The casing 1 comprises a closing flap 14 originating from the second wall 12 and which is extends beyond an opening 15 of the casing 1 delimited between the walls 11, 12 and the bellows 13. Opposite the flap 14, the casing 1 comprises a tab 16 coming from the second wall 12, folded over the first wall 11 and glued thereto to form a bottom. The envelope 1 can be closed by folding the closing flap 14 along a flap line 150 extending along the opening 15 and separating the closing flap 14 from the second wall 12, then folding the flap 14 on the first wall 11, as detailed below.

The closure flap 14 comprises on an inner face 140 a first adhesive layer 141 extending parallel to the flap line 14 and a second adhesive layer 142 extending parallel to the flap line 14 between said line and the first adhesive layer 141. The first and the second adhesive layer 141, 142 are separated by a separation space 144. A sheet 17 forming protection means covers the first adhesive layer 141 and the second adhesive layer 142 to protect them. The sheet 17 is for example a silicone paper.

The flap 14 is pre-cut by a first and a second line of weakness 181, 182 in the separation space 144, as is the sheet 17 which has a third line of weakness 183 aligned with the first line of weakness 181 and a fourth line of weakness 184 aligned with the second line of weakness 182. A third adhesive layer covers the separation space 144 between the lines of weakness to bond the sheet 17 and the flap 14 between them between the lines of weakness. weakening 181, 182, 183, 184. In the example shown, the lines of weakness 181, 182, 183, 184 are lines of perforations. The flap 14 has a notch 145 at one of the ends of the first and the second line of weakening 181, 182.

When using such an envelope 1, a user introduces a content, not shown, into the envelope 1 through the opening 15, then detaches the part of the sheet 17 which covers the first adhesive layer 141 by tearing it along the fourth line of weakness 184, as shown in FIG. 2, leaving a portion 17a of the sheet. He folds down the flap 14 by folding it along the flap line 14 and presses the first adhesive layer 141 on the first wall 11 so as to obtain the bonding of the flap 14 on the latter. Envelope 1 is then closed, as shown in Fig. 3, and can be sent.

When he receives the envelope 1, the recipient pulls on the assembly formed by the flap part 14 located between the weakening lines 181, 182 and the corresponding part of the sheet 17. For this, it is helped by the notches 145 which delimits a primer. The part which detaches forms a strap 146 which separates the flap 14 into two parts 14a, 14b, as shown in FIG. 4, one 14a which remains glued to the first wall 11, and another 14b which opens and releases the opening 15, as shown in FIG. 5.

Envelope 1 can be reused by the recipient. To do this, he removes the rest of the sheet 17a to release the second adhesive layer 142, he folds the flap 14 along the flap line 150 and presses the second adhesive layer 142 onto the first wall 11 so as to obtain the bonding. of the flap portion 14b thereon, as shown in FIG. 6.

Alternatively, the weakening lines can be pre-cut lines in the thickness of the flap 14 and of the sheet 17.

To manufacture an envelope 1 as described previously, a machine such as shown schematically in FIG. 7. Such a machine comprises successively in the unwinding direction an unwinding device 2 for unwinding a strip 3 of flexible material such as roll paper to unwind it, perforation means 4 for making perforations transversely on the strip 3 of material, depositing means 5, a casing forming device 6 for forming a casing from the strip 3 of material, a separation device 7 for separating a section 3' of the casing at the front of the casing by forming the closing flap 14 at a rear end of the section 3' of hose, weakening means 8 and a bottom-forming device 9 to form the casing 1 with each section 3' of hose by closing the front of the section 3 ' of casing. The formed envelopes 1 are stored in a stack at the outlet of the bottom forming device 9.

The casing forming device 6 is conventional and will not be described in more detail. The separation device 7 comprises a holding station 71 and a tear-off station 72 as described in document WO 2016/097310 A1. The operation of this separation device 7 is not repeated here, except that it makes it possible to provide the weakening means 8 with sections 3' of hose comprising a tab 16 at the front of the section 3', which will then allow to form the bottom of the envelope 1, and the flap 14 at the rear of the section 3', the second wall 12 being located in the lower part. Waste, not shown, is extracted from the casing by the tear-off station 72 and suction means 73 to uncover the flap 14.

The bottom formation device 9 is conventional and will not be described in more detail. It makes it possible to fold and glue tab 16 to close the envelope.

The deposition means 5 are provided for depositing the first, the second and the third adhesive layer 141, 142, 143 on the strip 3 of material and covering them with the sheet 17 at the level of what will become the flap 14 for closure. For this, the sheet 17 arrives continuously, is cut by a cutting station 51 and receives the adhesive layers in a gluing station 52. Then, it is taken up by a transfer station 53 which sucks it up to the surface of a roller 530 and presses it onto the strip 3 of material to deposit the sheet 17 and the adhesive layers 141, 142, 143. The face of the sheet 17 in contact with the adhesive layers 141, 142, 143 is siliconed in such a way that the sheet 17 can then be extracted while the adhesive layer 141, 142, 143 remains on the strip 3 of material.

The weakening means 8 comprise two notched blades 81, 82 projecting from a roller 83 and a counter-roller 84 comprising a flexible surface. By pinching the flap 14 of the section 3' of casing between the roller 83 and the counter-roller 84, the first line of weakening 181 and the third line of weakening 183 are produced on the flap 14 and the sheet 17 respectively aligned and in the separation space 144 of the flap 14, and the second line of weakness 182 in the separation space 144 of the flap 14 aligned with the fourth line of weakness 184 of the sheet 17, the lines of weakness having the form of lines of perforations.

In a second embodiment, the machine, as shown in FIG. 8, differs from that of the first embodiment in that the removal means 5' are located downstream of the device for separating the casing 7 and upstream of the weakening means 8.

The invention is not limited to the embodiments which have just been described solely by way of example. The envelopes can be made without gussets, i.e. the first wall and the second wall are joined together by a simple fold along the outer edges. The weakening means could be placed between the removal means and the casing forming means.

Claims

Envelope comprising an opening (15) and a closing flap (14) for closing the opening (15), the closing flap (14) being hinged on a first wall (11) of the envelope (1) and comprising on an inner face (140) a first adhesive layer (141) protected by protection means (17), a second adhesive layer (142) protected by the protection means (17) and separated from the first adhesive layer (141) by a separation space (144), the flap (14) being pre-cut by a first and a second line of weakness (181, 182) in the separation space (144), characterized in that the protection means are formed by a sheet (17) extending over the two adhesive layers (141, 142), the sheet (17) having a third line of weakness (183) aligned with the first line of weakness (181) and a fourth line line (184) aligned with the second line of weakening (182).
Envelope according to Claim 1, in which the sheet (17) and the flap (14) are glued between the lines of weakness (181, 182, 183, 184).
Envelope according to one of Claims 1 or 2, in which the lines of weakness (181, 182, 183, 184) are lines of perforations.
Envelope according to one of Claims 1 or 2, in which the lines of weakness (181, 182, 183, 184) are pre-cut lines in the thickness.
Envelope according to one of the preceding claims, characterized in that it comprises a second wall (12), from which the flap (14) originates, and connected to the first wall (11) along external edges (110) of the first wall (11).
Envelope according to Claim 5, in which the first and the second wall (11, 12) are connected by gussets (13) extending along the outer edges (110).
Envelope according to one of the preceding claims, in which the flap (14) comprises a notch (145) at at least one of the ends of at least one of the lines of weakness.
Method of manufacturing an envelope (1) according to one of claims 1 to 7, according to which a closure flap (14) is formed in the extension of a second wall (12) of the envelope (1), two adhesive layers parallel to each other and separated by a separation space (144) are deposited on the flap (14), characterized in that a sheet (17) forming protection means (17) is deposited on the two adhesive layers, the sheet (17) and the flap (14) are weakened together to produce a first line of weakening in the separation space (144) of the flap (14) aligned with a third line of perforation in the sheet (17), and a second line of perforation in the dividing space (144) of the flap (14) aligned with a fourth line of weakness in the sheet (17), the lines of weakness extending parallel in the separation space (144).
Process according to Claim 8, in which the envelope (1) is formed from a strip (3) of flexible material on which the adhesive layers and the protective sheet (17) are first deposited, then the strip (3) is closed in a hose by joining the widths of the strip (3), then the hose is separated into sections leaving the flap (14) at a first end of the section (3 '), each section ( 3') forming an envelope (1) after closing a second end opposite the first end.
A method according to claim 9, wherein the lines of weakness are made after the casing has been separated into sections.
Process according to Claim 8, in which the casing (1) is formed from a strip (3) of flexible material closed up in a casing by joining the lengths of the strip (3), then the casing is separated into sections leaving the flap (14) remaining at a first end of the section (3'), each section (3') forming an envelope (1) after the closure of a second end opposite the first end, and flap (14) on which are carried out the removal of the adhesive layers, the protective sheet (17) and the lines of weakness (181, 182, 183, 184).
Machine for manufacturing an envelope (1) implementing a method according to one of Claims 8 to 10, the machine comprising a casing-forming device (6) for forming a casing from a strip (3) of flexible material, a separation device (7) for separating a section (3') of the casing at the front of the casing by forming a closing flap (14) at one of the ends of the section (3') of casing , the flap (14) extending the section (3') beyond the end of a first wall (11), the machine being characterized in that it comprises depositing means (5, 5') for depositing on the strip (3) of material two adhesive layers parallel to each other and separated by a separation space (144) at the level of the closing flap (14), the depositing means (5, 5') being provided for further depositing a sheet (17) forming protection means on the two adhesive layers, the machine further comprising weakening means (8) for producing together a pr first line of weakness and a third line of weakness on respectively the shutter (14) and the sheet (17) aligned and in the separation space (144) of the shutter (14), and together a second line of weakness in the separation space (144) of the flap (14) aligned with a fourth line of the sheet (17), the lines of weakness extending parallel in the separation space (144).
Machine according to Claim 12, in which the depositing means (5) are located upstream of the casing-forming device (6).
Machine according to Claim 12, in which the depositing means (5') are located downstream of the separation device (7).
Machine according to one of Claims 12 to 14, in which the weakening means (8) are located downstream of the device for separating the casing (7) and the depositing means (5, 5').
Machine according to one of Claims 12 to 15, characterized in that it comprises a bottom-forming device (9) for forming the casing (1) with each section (3') of casing by closing the front of the section (3') of hose.